This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A014401 #21 Mar 22 2022 21:27:54
%S A014401 48,768,30720,2211840,247726080,39636172800,8561413324800,
%T A014401 2397195730944000,843812897292288000,364527171630268416000,
%U A014401 189554129247739576320000,116765343616607579013120000
%N A014401 Denominators of coefficients of expansion of Bessel function J_3(x).
%D A014401 Bronstein-Semendjajew, Taschenbuch der Mathematik, 7th german ed. 1965, ch. 4.4.7
%H A014401 T. D. Noe, <a href="/A014401/b014401.txt">Table of n, a(n) for n=0..50</a>
%H A014401 <a href="/index/Be#Bessel">Index entries for sequences related to Bessel functions or polynomials</a>
%F A014401 a(n) = 2^(2n+k) * n! * (n+k)! here for k=3, i.e., Bessel's J3(x).
%F A014401 D-finite with recurrence: a(n) - (4*n^2 + 4*n*k)*a(n-1) = 0, a(0) = 2^k*k!, here for k=3. - _Georg Fischer_, Mar 22 2022
%e A014401 a(1) = 768 = 32*24, J3(x) = x^3/48 - x^5/768 + x^7/30720 - x^9/2211840 +- ...
%p A014401 k:=3: f:= gfun:-rectoproc({a(n)-(4*n^2 + 4*n*k)*a(n-1), a(0)=2^k*k!}, a(n), remember): map(f, [$0..16]); # _Georg Fischer_, Mar 22 2022
%t A014401 Denominator[Take[CoefficientList[Series[BesselJ[3,x],{x,0,30}],x],{4,-1,2}]] (* _Harvey P. Dale_, Dec 10 2011 *)
%Y A014401 J0: A002454, J1: A002474, J2: A002506.
%K A014401 nonn
%O A014401 0,1
%A A014401 _N. J. A. Sloane_